Adventures in Machine Learning

Understanding Absolute Values: Definition Properties and Python Implementation

Understanding Absolute Values: Defining Magnitude and Direction

Absolute values are an essential concept in mathematics. They are used to define the magnitude or size of a number, vector, or complex number.

In simpler terms, the absolute value of a number tells us its distance from zero on the number line, regardless of its sign. For instance, the absolute value of -4 is 4, and the absolute value of 5 is also 5.

Absolute values are crucial in various fields of study, including physics, engineering, and computer science. They help to define direction and magnitude, which are vital in understanding complex equations and calculations.

In this article, we will explore the definition of absolute values, their mathematical properties, and how to implement them in Python.

Mathematical Definition of Absolute Values

Mathematically, absolute values can be defined as a piecewise function. A piecewise function comprises different functions defined over different intervals of the domain.

In this case, the absolute value function can be defined as follows:

| x | = { x if x >= 0; -x if x < 0 }

This function is also represented by vertical lines enclosing a number or expression, such as |5| or |-3x|. The basic idea of the absolute value function is to strip a number of its sign and return a positive value.

For example, the absolute value of -3 is |-3| = 3.

Absolute Value and Vectors

Vectors are used in physics and engineering to describe the direction and magnitude of a physical quantity such as velocity or force. The Euclidean norm or length of a vector can be determined by taking the square root of the sum of the squares of its components.

For instance, the Euclidean norm of a two-dimensional vector (a, b) can be computed as follows:

(a, b) = sqrt(a^2 + b^2)

The absolute value of a vector is simply its magnitude or length. It tells us the straight-line distance between the initial and terminal points of a vector.

For example, the absolute value of a snowflake vector from point (2, 1) to point (5, 4) is:

(5 – 2, 4 – 1) = (3, 3) = sqrt(3^2 + 3^2) = 32

A vector is said to be bound if it has a fixed initial and terminal point. It is free if its initial and terminal points can change.

Free vectors are useful in physics and engineering, while bound vectors are more useful in mathematics.

Absolute Value and Complex Numbers

Complex numbers are used to represent quantities with real and imaginary parts. A complex number can be represented as a + bi, where a and b are real numbers, and i is the imaginary unit, defined as the square root of -1.

The absolute value or modulus of a complex number is defined as its distance from the origin in the complex plane. Mathematically, it is given by:

|z| = sqrt(a^2 + b^2)

where a is the real part of the complex number and b is the imaginary part.

The modulus of a complex number has various applications, including calculating the phase angle of a signal in electrical engineering and measuring the strength of a wave in physics.

Implementation of the Absolute Value Function in Python

Python is a popular programming language used for scientific computing, data analysis, and machine learning. It provides several built-in functions that can be used to compute the absolute value of a number, including integers, floating-point numbers, fractions, and complex numbers.

The abs() function is a built-in function that can be used to compute the absolute value of a number in Python. To implement the abs() function from scratch, we can use conditional statements or expressions to check the sign of a number and return its absolute value.

For example:

def absolute_value(x):

if x >= 0:

return x


return -x

This function takes a number x as input and returns its absolute value using conditional statements. Alternatively, we can use the built-in abs() function to compute the absolute value of a number in Python.

The abs() function can take various data types as input, including numbers, lists, NumPy arrays, pandas Series, and DataFrames. For example, to compute the absolute value of a list of numbers, we can use the map() function to apply the abs() function to each element of the list, as follows:

numbers = [-3, 4, -2.5, 6]

abs_numbers = list(map(abs, numbers))


This code returns a list of the absolute values of the numbers in the original list.


In conclusion, absolute values are essential in mathematics and various fields of study. They help to define the magnitude and direction of a number, vector, or complex number.

The absolute value function can be defined algebraically or geometrically using different mathematical expressions. In Python, we can implement the absolute value function from scratch or use the built-in abs() function to compute the absolute value of various data types.

In summary, understanding absolute values is crucial in various fields of study, including physics, engineering, and computer science, as they help to define magnitude and direction. They are used in mathematical calculations, particularly in the computation of the length of vectors or the modulus of complex numbers.

In Python, the abs() function can be used to calculate the absolute value of different data types. By mastering the concepts of absolute values and knowing how to implement them, one can have a better understanding of complex equations and calculations, making mathematical applications in various fields more accessible.